Phage-based dual-mode sensor using ECL and EIS for sensitive detection of Pseudomonas Aeruginosa

Area of Science:

• Biomedical Engineering
• Microbiology
• Analytical Chemistry

Background:

• Pseudomonas aeruginosa infections pose significant risks, especially to vulnerable populations.
• Rising antibiotic resistance necessitates advanced diagnostic tools for early and accurate detection.
• Current detection methods may lack the specificity or speed required for timely intervention.

Purpose of the Study:

• To develop and validate a novel biosensor for the sensitive and specific detection of Pseudomonas aeruginosa.
• To leverage bacteriophage M-PAP1 for high target recognition combined with electrochemical techniques.
• To establish a dual-mode (ECL and EIS) detection system for enhanced reliability and reduced false positives.

Main Methods:

• Fabrication of a modified screen-printed electrode (SPE) with MWCNT-COOH and immobilization of bacteriophage M-PAP1.
• Application of electrochemical luminescence (ECL) and electrochemical impedance spectroscopy (EIS) for signal transduction.
• Testing sensor performance using standard solutions and artificial urine samples, assessing parameters like limit of detection (LoD), linear range, recovery, and selectivity.

Main Results:

• The ECL sensor achieved a low LoD of 0.755 CFU ml⁻¹ with a wide linear working range (2.28 to 10¹⁰ CFU ml⁻¹).
• High recovery rates (92%–97%) were observed in artificial urine samples, demonstrating applicability in biological matrices.
• The biosensor exhibited excellent selectivity, with minimal interference from common non-specific bacteria like Escherichia coli and other Pseudomonas species.

Conclusions:

• The M-PAP1-based dual-mode biosensor provides a highly sensitive, specific, and reliable platform for Pseudomonas aeruginosa detection.
• The combined ECL and EIS approach enhances diagnostic accuracy through cross-validated signals.
• This versatile system holds significant potential for rapid, real-time clinical monitoring of P. aeruginosa infections, addressing the challenge of antimicrobial resistance.